Researchers develop high-energy-density flexible supercapacitors taking advantage of transition metal nitrides.
Transition metal nitrides (TMNs) are potential electrode materials for high-performance energy storage devices, but the structural instability severely hinders their application. Therefore, it is highly important to construct advanced cathode materials for flexible, wearable, long-life and high-energy-density energy storage devices.
A research team led by Prof. Zhao Bangchuan from the Institute of Solid Materials of the Hefei Institutes of Physical Science (HFIPS) have constructed a high-energy-density flexible supercapacitor device by synthesizing 3D porous honeycomb-like CoN-Ni3N/N-C nanosheets and vanadium nitride (VN) nanobelt arrays via ion-site growth method, respectively. 
Experiments suggest that the intrinsic conductivity was enhanced, and concentration of the active sites was increased. This, according to the researchers, gives advantage to the optimized CoN-Ni3N/N-C/CC, which can be used as an integrated electrode for the supercapacitor to achieve remarkable electrochemical performance.
The developed supercapacitor delivers an energy density of 106 μWh per cm^2 with maximum power density of 40 mW cm^-2 with high stability.
According to the researchers, this work provides a viable strategy to construct high-energy flexible wearable electronics in the next-generation electrochemical energy storage field.
The research appeared in the journal Advanced Functional Materials.